Richard Wallace, the man behind the UK's greatest art collection

All the girls are in love with me,” wrote the 17-year-old Lord Beauchamp to his mother in Paris, in 1817. “I have dinners, parties, and balls almost every night (I say this entre nous).”

He might have intended his behaviour to remain "entre nous", but things didn’t quite pan out that way. Nine months later, a Mrs Agnes Jackson, née Wallace, gave birth to a son, Richard. When he was six, she took him to Paris and deposited him with Beauchamp, by then Lord Yarmouth, and first in line to the marquisate of Hertford.

So similar were boy and man in looks, that Yarmouth’s mother took Richard in, recognising him as her son’s child. He grew up surrounded by luxury, in the bosom of the family, at a time...